Descaling apparatus



May 12., 1970 F. GALLUCCI ETAL 3,511,250

DESCALING APPARATUS Filed July 25', 1968 2 Sheets-Sheet l 45 INVENTORS FRANCIS GALLUCC/ 8 GOTTFR/ED HOFMAN/V Byway 7 42b:

A Horney May 12, 1970 F. GALLUCCI ETAL 3,511,250

DESCALING APPARATUS Filed July 25, 1968 2 Sheets-Sheet 2 TEE-.3-

lNl/E/VTORS FRANCIS GAL/.UCC/ 8 GOTTFR/ED HOFAMN/V A/ramey United States Patent 3,511,250 DESCALING APPARATUS Francis Gallucci, North Huntington Township, Westmoreland County, and Gottfried Hofmann, Brentwood Borough, Pa., assignors to United States Steel Corporation, a corporation of Delaware Filed July 25, 1968, Ser. No. 747,560 Int. Cl. B08b 3/02 US. Cl. 134122 8 Claims ABSTRACT OF THE DISCLOSURE An apparatus for descaling metal slabs produced in a continuous-casting operation. Before the slabs are rolled, they pass through the descaling apparatus. The apparatus includes carriages which are propelled back and forth above and below the slab and high pressure jet nozzles on each carriage. Water from nozzles removes scale from slab surfaces without unduly cooling the slab.

This invention relates to an improved apparatus for descaling metal slabs at high temperatures.

Although our invention is not thus limited, our apparatus is particularly useful for descaling steel slabs produced in a continuous-casting operation. One form of continuous-casting machine with which our descaling apparatus may be used includes a water-cooled mold open at both ends, trains of vertically spaced guide rolls below the mold, a set of power-driven pinch rolls below the guide rolls, and a curved casting guide below the pinch rolls. Before a casting operation begins, a starter bar is inserted upwardly through the pinch rolls and guide rolls to the mold. A stream of molten metal is poured through the mold into contact with the starter bar, which descends through the guide rolls and pinch rolls ahead of the resulting slab. As the slab passes the guide rolls, water sprays are applied to its surface to aid in solidifying it. Initially the leading end of the slab attaches itself to the starter bar, but the starter bar is disconnected as the slab reaches the pinch rolls. After the starter bar is disconnected, bending rolls within the casting guide bend the slab 90 so that it travels horizontally. The horizontal slab is reheated and travels through a series of work-roll stands. Before the slab reaches the latter, it is descaled by applying water jets to its surface, but these jets should not unduly cool the slab prior to rolling.

An object of our invention is to provide an improved descaling apparatus which applies water jets at high pressure and low volume to a slab, thereby eifectively removing scale from its surface without unduly cooling it.

A further object is to provide a descaling apparatus which affords the foregoing advantages and includes means for automatically traversing the jets back and forth across both the upper and lower surfaces of a slab.

In the drawings:

FIG. 1 is a front elevational view of our descaling apparatus;

FIG. 2 is a horizontal section on line II-II of FIG. 1;

FIG. 3 is a vertical section on line III III of FIG. 1; and

FIG. 4 is an end view of one of the nozzles embodied in our apparatus.

Our descaling apparatus includes opposed pairs of upper and lower vertical frame members and 12 situated above and below a slab S. The slab is at a high temperature and it travels continuously in a horizontal direction perpendicular to the plane of FIG. 1. The upper frame members 10 carry respective brackets 13, be tween which extend a pair of horizontal upper guide 3,511,250 Patented May 12, 1970 rods 14 spaced above the slab. Similarly the lower frame members 12 carry brackets 15 and lower guide rods 16 spaced below the slab.

We mount an upper carriage 17 on the upper guide rods 14 and a lower carriage 18 on the lower guide rods 16, both carriages being movable along their rods transversely of the slab. Each carriage is of a length approximate- 1y equal to the distance it travels or half the slab width. We journal a pair of pulleys 19 to the upper brackets 13 at opposite ends of the upper guide rods, and another pair of pulleys 20 to the lower brackets 15 at opposite ends of the lower guide rods. We connect a pair of flexi- -ble strands 21 to carriages 17 and 18 and extend each strand around a pulley 19 at the top and a pulley 20 below, whereby movement of the upper carriage 17 moves the lower carriage 18 the same distance but in the opposite direction. The top of the upper carriage 17 has a pair of arms 24 which extend laterally toward both sides (FIG. 3). The bottom of the lower carriage 18 has a pair of laterally extending arms 25. We attach the strands 21 to arms 24 and 25 through eye bolts 26, at least one of which carries a spring 27 to maintain the strands taut. Preferably each bracket 13 and 15 carries a respective spring-pressed bumper 28 to cushion the carriages when they reach the ends of the rods. Preferably also we cover the four rods 14 and 16 with telescoping shields 29 connected at their ends to the brackets 13 or 15 and to the carriages 17 and 18. The shields and carriages protect the rods against dust and scale.

A transverse beam 32 extends between the upper frame members 10 spaced above the upper guide rods 14. The beam carries a double-acting fluid pressure cylinder 33, the piston of which has piston rods 34 extending from both ends of the cylinder. We journal pulleys 35 to the ends of the piston rod. We connect additional flexible strands 36 to brackets 37 fixed to beam 32 above cylinder 33. These strands extend around pulleys 35 and are connected at their other ends to the aforementioned arms 24 (FIG. 3). We connect a source of fluid under pressure to cylinder 33 through a four-way valve 38, which has horizontally movable operating levers 39 extending in both directions for engagement by the piston rods 34 at the ends of their strokes. An example of a suitable valve is the Vickers Rotary Type Directional Valve. The valve alternately admits fluid to cylinder 33 to drive the piston and piston rods 34 first in one direction and then in the other. The pulleys 35 and strands 36 transmit this motion to the upper carriage 17, which in turn drives the lower carriage 18 in the opposite direction, as already explained. When the piston reaches the ends of its stroke in either direction, the end of one piston rod 34 abuts one of the levers 39 to reverse the valve. It is seen that the pulley arrangement moves the carriages through twice the distance the piston rods move.

The underside of the upper carriage 17 carries two downwardly directed nozzles 42 near its ends. Similarly the top of the lower carriage 18 carries two upwardly directed nozzles 43. Each nozzle extends outwardly from its carriage at an angle of about 15 to the vertical. Water is introduced to the nozzles through flexible hoses 44 and 45 connected to the respective carriages and distributors 46 and 47 fixed to the carriages. As FIG. 4 shows, the nozzles have narrow rectangular openings 49 elongated in the direction of slab travel to direct knife-edge water jets against the surfaces of the slab.

In operation, the cylinder 33 drives the carriages 17 and 18 back and forth continuously above and below the slab S. The nozzles 42 and 43 direct jets of water at high pressure and low volume against the slab surfaces. Thus the jets effectively remove scale from the slab to prepare it for rolling without unduly cooling it.

While We have shown and described only a single embodiment of our invention, it is apparent that modifica-- tions may arise. Therefore, we do not wish to be limited to the disclosure set forth but only by the scope of the appended claims.

We claim:

1. A descaling apparatus comprising upper and lower supports between which a slab can travel, upper and lower carriages mounted on the respective supports for movement transversely of the slab, drive means operatively connected with said carriages for propelling them back and forth above and below the slab, a pair of downwardly and outwardly directed nozzles carried by said upper carriage, a pair of upwardly and outwardly directed nozzles carried by said lower carriage, and means for introducing water to said nozzles, said nozzles being adapted to direct high pressure low volume jets of Water against the upper and lower surfaces of the slab.

2. An apparatus as defined in claim 1 in which each of said carriages is of a length equal to approximately the distance it travels and said drive means propels said carriges in opposite directions.

3. An apparatus as defined in claim 2 in which said drive means includes a double-acting fluid pressure cylinder supported above said upper carriage, piston rods extending from opposite ends of said cylinder, and flexible strands and pulleys for transmitting motion of said piston rods to said carriages.

4. An apparatus as defined in claim 3 further comprising a reversing valve connected to said cylinder and operated by said piston rods at the ends of their strokes.

5. An apparatus as defined in claim 3 in which there are respective pulleys journaled to the ends of each of said piston rods, strands connected at one end above said cylinder, extending around the pulleys on said piston rods, and connected at the other end to opposite ends of said upper carriage, and in which there are pulleys journaled at each end of said upper and lower supports and strands connected at opposite ends to said upper and lower carriages and extending around said last-named pulleys.

6. An apparatus as defined in claim 1 in which said upper support includes a pair of horizontal guide rods and said lower support includes another pair of horizontal guide rods, said apparatus further comprising telescoping shields connected to said carriages and covering said rods.

7. An apparatus as defined in claim 6 further comprising spring-pressed bumpers mounted on said supports to be engaged by said carriages at the ends of their movement in either direction.

8. An apparatus as defined in claim 1 in which said nozzles have openings elongated in the direction of slab travel to produce knife-edge jets.

References Cited UNITED STATES PATENTS 2,342,533 2/1944 Edwards. 2,576,861 11/1951 Shaw et a1 134l22 XR 3,126,301 3/1964 Faler 134-64 XR 3,200,656 8/1965 Baskett 118-323 XR 3,288,109 11/1966 Smith et al 1183 16 ROBERT L. BLEUTGE, Primary Examiner US. Cl. X.R. 

